Thanks for this. It worked for me, Mac OS running Sierra.
Had to update XCode, install tools, install Ruby, RVM, Rails, brew install ffmpeg.
Took a while to download and install, then update all that stuff.

Then follow your instructions. I had to include the '--silk-decoder' argument followed by the path to the Directory with all the .aud files.
Now I've 2000 .wav files. No timestamps but I'm just happy to have them in a consumable format. Happy memories for the rainy day.
/ V, from Ireland